Phosgene Oxime Exposure Clinical Presentation

Updated: Oct 26, 2023
  • Author: Erik D Schraga, MD; Chief Editor: Zygmunt F Dembek, PhD, MS, MPH, LHD  more...
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Important historic features of a potential toxic chemical exposure include the following:

  • Estimated time of occurrence
  • Duration and circumstances of exposure
  • Onset and time course of symptoms
  • Odor and/or color of gases or vapors
  • Protective clothing worn (if any)
  • Effects on surroundings (eg, other human or animal casualties)

Phosgene oxime (CX) casualties typically report unbearable pain in exposed skin and eyes; difficulty with sight or blindness after ocular exposure; and sore throat, hoarseness, dyspnea, chest pain, and cough after respiratory exposure.

Some casualties may experience a peppery or pungent odor during their initial CX vapor exposure, but this is typically lost quickly because of accommodation.

When mixed with another chemical agent (eg, VX), the rapid skin damage caused by phosgene oxime enables a greater dermal susceptibility to the second agent. [13]


Physical Examination


A blanching, grayish skin lesion surrounded by an erythematous ring can be observed within 30 seconds of exposure. [14] A wheal develops on exposed skin within 30 minutes. The original blanched area acquires a necrotic, brown pigmentation by 24 hours. An eschar forms in the pigmented area by 1 week and sloughs after approximately 3 weeks. Healing may be incomplete 4 to 6 months post-exposure. [13]


Eye examination typically demonstrates pain, conjunctivitis, lacrimation, lid edema, and blepharospasm after even minute exposures. More severe exposures can result in keratitis, iritis, corneal perforation, and blindness.


Irritation of the mucous membranes may be observed on examination of the oropharynx and nose. Evidence of pulmonary edema, including rales and wheezes, may be noted on auscultation. Necrotizing bronchiolitis and pulmonary venule thromboses are prominent features of severe CX exposure. [15]

Systemic effects

Animal data suggest that topical CX exposure may result in dilation of the peripheral blood vessels and a significant increase in red blood cells in vessels of the liver, spleen, kidney, lungs, and heart. These events could cause a drop in blood pressure, leading to shock, hypoxia, and death. [14]